Surgical devices and methods utilizing optical coherence tomography (OCT) to monitor and control tissue sealing

ABSTRACT

Surgical devices and methods for utilizing optical coherence tomography (OCT) to monitor and control tissue sealing are disclosed. The surgical device includes an end effector assembly that includes first and second jaw members that are movable between a first, spaced-apart position and a second proximate position. An OCT system, at least a portion of which is incorporated into the end effector assembly, is configured to sense properties of the tissue, e.g., the structural density of the tissue, disposed between the first and second jaw members. A tissue-sealing energy source may be disposed within at least one of the jaw members and may provide tissue-sealing energy to tissue disposed between the jaw members. A controller, which is coupled to the OCT system and the tissue-sealing energy source, controls the tissue-sealing energy generated by the tissue-sealing energy source based on the properties of the tissue sensed by the OCT system.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 14/052,827, filed on Oct. 14, 2013, which claims the benefit ofand priority to U.S. Provisional Patent Application Ser. No. 61/720,817,filed on Oct. 31, 2012. The entire contents of each of the foregoingapplications are hereby incorporated herein by reference.

BACKGROUND Technical Field

The present disclosure relates to surgical forceps having opticalcomponents for monitoring and controlling tissue sealing. Moreparticularly, the present disclosure relates to open or endoscopicforceps that incorporates Optical Coherence Tomography (OCT) systemcomponents to monitor and to provide feedback for controlling a tissuesealing.

Description of Related Art

Existing energy-based tissue-sealing surgical forceps use differenttypes of energy to heat tissue. The different types of energy used toheat tissue include direct heat conduction from a heating element, RFcurrent, ultrasound, and light. A typical energy-based tissue-sealingsurgical forceps includes jaw members for grasping and compressing thetissue and applying energy to the tissue.

During a surgical procedure, it is important for a surgeon to be able todetermine the status of a tissue seal, e.g., the quality of a tissueseal. This feedback allows a surgeon to appropriately operate thetissue-sealing surgical forceps to create a high-quality tissue seal.Existing tissue-sealing surgical forceps and associated systems may notprovide sufficient information about the status of a tissue seal.

SUMMARY

As used herein, the term “distal” refers to that portion that is furtherfrom an operator while the term “proximal” refers to that portion thatis closer to an operator. As used herein, the term “treat” refers toperforming a surgical treatment to tissue including, but not limited toheating, sealing, cutting, sensing, and/or monitoring.

As used herein, the term “light source” broadly refers to all types ofdevices or elements that generate or transmit light for medical use(e.g., tissue treatment). These devices include lasers, light emittingdiodes (LEDs), lamps, and other devices that generate light having awavelength that is within the light spectrum (e.g., from infrared lightto ultraviolet light). Also, the light sources described herein may beused interchangeably. For example, an LED light source may be usedinterchangeably with a laser light source.

As described in more detail below with reference to the accompanyingfigures, the present disclosure relates to open or endoscopic surgicalforceps that incorporates optical and electrical components forperforming Optical Coherence Tomography (OCT) to image tissue fordiagnostic or identification purposes, or to image a tissue seal after atissue sealing cycle to determine the quality of the tissue seal. Insome embodiments, the optical components use broadband, infrared lighthaving a wavelength of between 800 and 1550 nm to image subsurfacetissue structures at depths of a few millimeters and with a resolutionon the order of micrometers.

The optical components may include reference arm optics disposed in afirst jaw member of the surgical forceps and sample arm optics disposedin a second jaw member opposite the first jaw member. The opticalcomponents also include a light source configured to generate broadbandlight and transmit the broadband light to the reference arm and thesample arm. The optical components further include a light detector thatdetects an interference pattern in the broadband light that is reflectedback from the reference arm optics and the sample arm optics. Theelectrical components may include a signal processor that processes thedetected interference pattern and displays an image of the sealed tissueon a display device.

The optical components may further include a aiming light source forgenerating an aiming beam and an optical coupler that optically couplesthe aiming beam to the broadband light before the resulting light istransmitted to the reference arm optics and the sample arm optics.

The OCT system may incorporate polarization optics to measurebirefringence to determine whether collagen has been denatured. In otherembodiments, the OCT system may be configured to perform opticalcoherence microscopy using a high numerical aperture for histology ortissue diagnostics. The numerical aperture (NA) refers to the resolvingpower of a lens. Values of NA that are greater than 1.2 may beconsidered high. The optical resolution is proportional to λ/(2×NA),where λ is the wavelength of the light.

The OCT system may be configured to perform color Doppler coherencetomography to measure tissue perfusion.

In one aspect, the present disclosure features a surgical device. Thesurgical device includes a housing and an end effector assembly operablycoupled to the housing. The end effector assembly includes first andsecond jaw members that each have a tissue contacting surface. At leastone of the first and second jaw members is movable between a first,spaced-apart position and a second proximate position. The end effectorassembly further includes a sample arm optical assembly of aninterferometer coupled to the first jaw member. The sample arm opticalassembly transmits a first light beam to tissue grasped between thefirst and second jaw members and receives at least a portion of thefirst light beam reflected from the tissue.

The end effector assembly also includes a reference mirror of theinterferometer coupled to the second jaw member. The end effectorassembly further includes a reference arm optical assembly of theinterferometer coupled to the second jaw member. The reference armoptical assembly transmits a second light beam to the reference mirrorand receives at least a portion of the second light beam reflected fromthe reference mirror.

The sample arm optical assembly may include movable sample arm opticsthat scan the first light beam across the tissue. The sample arm opticalassembly may include a light guide operable to translate and rotate withrespect to a longitudinal axis of the first jaw member to scan thetissue.

The reference arm optical assembly may translate along a longitudinalaxis of the second jaw member. Alternatively, the reference mirror maytranslate along a longitudinal axis of the second jaw member.

The first jaw member may be a top jaw member and the second jaw membermay be a bottom jaw member.

The surgical device may further include an optical coupler opticallycoupled to the sample arm optical assembly and the reference arm opticalassembly. The optical coupler may provide a first light beam through afirst output of the optical coupler to the sample arm optical assemblyand may provide a second light beam through a second output of theoptical coupler to the reference arm optical assembly.

The surgical device may include an imaging light source that generatesimaging light. The imaging light source may be optically coupled to aninput of the optical coupler.

The surgical device may further include a visible light source thatgenerates visible light and a second optical coupler having a firstinput, a second input, and an output. The first input of the secondoptical coupler may be optically coupled to the imaging light source andthe second input of the second optical coupler may be optically coupledto the visible light source. The second optical coupler may combine theimaging light and the visible light and to transmit the combined lightout of the output of the second optical coupler.

A portion of the housing of the surgical device may form a handle andthe imaging light source and the visible light source may be disposedwithin the handle.

The sample arm optical assembly may include polarization optics to allowfor birefringence. Alternatively, the sample arm optical assembly andthe reference arm optical assembly may be configured for opticalcoherence microscopy using a high numerical aperture.

In another aspect, the present disclosure features a system for treatingtissue. The system includes a surgical device and a processor. Thesurgical device includes a housing and an end effector assembly operablycoupled to the housing. The end effector assembly includes first andsecond jaw members that each have a tissue contacting surface. At leastone of the first and second jaw members is movable between a first,spaced-apart position and a second proximate position. The end effectorassembly further includes a sample arm optical assembly of aninterferometer coupled to the first jaw member. The sample arm opticalassembly transmits a first light beam to tissue grasped between thefirst and second jaw members and receives at least a portion of thefirst light beam reflected from the tissue.

The end effector assembly also includes a reference mirror of theinterferometer coupled to the second jaw member. The end effectorassembly further includes a reference arm optical assembly of theinterferometer coupled to the second jaw member. The reference armoptical assembly transmits a second light beam to the reference mirrorand receives at least a portion of the second light beam reflected fromthe reference mirror.

The end effector assembly further includes a light detector that detectsat least a portion of the first light beam reflected from the tissue andat least a portion of the second light beam reflected from the referencemirror and generates a light detection signal. The processor of thesystem for treating tissue is coupled to the light detector and isconfigured to process the light detection signal to obtain interferencepattern data. The processor may be configured to generate an imagesignal based on the interference pattern data and to transmit the imagesignal to a display device.

The system may further include an energy source coupled to at least oneof the first and second jaw members and a controller coupled to thelight detector and the energy source. The energy source delivers energyto the at least one of the first and second jaw members to seal tissueand the controller controls the energy source based on the at least onemeasured property of the light energy passing through the tissue. Atleast one of the energy source and the controller may be disposed withinthe housing.

In yet another aspect, the present disclosure features a method ofdetermining properties of tissue in an energy-based medical device. Themethod includes grasping tissue between first and second jaw members ofan energy-based medical device by moving at least one of the first andsecond jaw members between a first, spaced-apart position and a secondproximate position. The method further includes directing a first lightbeam to the tissue grasped between the first and second jaw members,receiving at least a portion of the first light beam reflected from thetissue, directing a second light beam to a reference mirror, receivingat least a portion of the second light beam reflected from the referencemirror, combining the at least a portion of the first light beamreflected from the tissue and the at least a portion of the second lightbeam reflected from the reference mirror to form an interference lightbeam, detecting the interference light beam, and determining at leastone tissue property based upon the detected interference light beam.

Determining at least one tissue property may include forming an image ofthe tissue based upon the detected interference light beam. The methodmay further include controlling the energy applied to the tissue by theenergy-based medical device based upon the at least one tissue property.The method may further include determining tissue seal quality,identifying the tissue, or diagnosing the tissue based upon the at leastone tissue property.

In one aspect, the present disclosure features a surgical device. Thesurgical device includes a shaft, an end effector assembly operablycoupled to the shaft, and a controller. The end effector assemblyincludes first and second jaw members, each of which has atissue-contacting surface. At least one of the first and second jawmembers is movable between a first, spaced-apart position and a secondproximate position. The end effector assembly further includes atissue-sealing energy source disposed within at least the first jawmember. The tissue-sealing energy source is configured to providetissue-sealing energy to tissue disposed between the first and secondjaw members.

The end effector assembly further includes an OCT probe configured tosense properties of tissue disposed between the first and second jawmembers. The controller is coupled to the OCT probe and thetissue-sealing energy source so that the controller can control thetissue-sealing energy generated by the tissue-sealing energy sourcebased upon the structural density of the vessel sensed by the OCT probe.

The OCT probe may be embedded within the second jaw member. Further, atleast a portion of the tissue-contacting surface of the first jaw membermay include a transparent optical element that allows light to passbetween the OCT probe and the tissue. Still further, the tissue-sealingenergy source may generate tissue-sealing light and a reflective elementmay be disposed on the surface of the transparent optical element toprevent the tissue-sealing light from passing through the transparentoptical element.

The OCT probe may be rotatably coupled to the second jaw member so thatthe OCT probe moves between a position parallel to the longitudinal axisof the second jaw member to a position perpendicular to the longitudinalaxis of the second jaw member. Alternatively, the OCT probe may bemovably coupled to the shaft so that the OCT probe can move out of theshaft between the first and second jaw members.

The surgical device may further include a second tissue-sealing energysource disposed within the second jaw member. The second tissue-sealingenergy source may be configured to provide tissue-sealing energy totissue disposed between the first and second jaw members.

The tissue-sealing energy source may generate electrical energy orultrasonic energy.

The controller may be configured to operate the OCT probe to sense atissue property prior to activating the tissue-sealing energy source.The controller may be additionally or alternatively configured tooperate the OCT probe to sense a tissue property while operating thetissue-sealing energy source.

The OCT probe may sense the structural density of the tissue disposedbetween the first and second jaw members. The controller may correlatethe sensed structural density of the tissue to the amount of collagencontained within the tissue disposed between the first and second jawmembers.

In another aspect, the present disclosure features a method of sealingtissue. The method includes grasping tissue between first and second jawmembers of a surgical device, sensing the structural density of thetissue disposed between the first and second jaw members using an OCTprobe, determining parameters for tissue-sealing energy based upon thestructural density of the tissue sensed by the OCT probe, and providingthe tissue-sealing energy to the tissue based upon the determinedparameters of the tissue-sealing energy.

The method of sealing tissue may also include inserting the OCT probe inbetween the first and second jaw members so that the distal end of theOCT probe is close to the tissue after the tissue is grasped between thefirst and second jaw members. The method may further include retractingthe OCT probe from in between the first and second jaw members after theOCT probe completes sensing the structural density of the tissue graspedbetween the first and second jaw members.

The method may include sensing the structural density of the tissuedisposed between the first and second jaw members using an OCT probeafter providing the tissue-sealing energy to the tissue, and determiningthe quality of the tissue seal based upon the sensed structural densityof the tissue.

The method may include rotating the OCT probe from a first positionparallel to the longitudinal axis of the second jaw member to a secondposition perpendicular to the longitudinal axis of the second jaw memberprior to activating the OCT probe to sense the structural density of thegrasped tissue.

The tissue-sealing energy may be electrical energy or ultrasonic energy.The method may include simultaneously operating the OCT probe to sensethe structural density of the tissue and to provide tissue-sealingenergy to the tissue. The method of sealing tissue may includecorrelating the sensed structural density of the grasped tissue to theamount of collagen and/or elastin contained within the grasped tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the subject instrument are described herein withreference to the drawings wherein:

FIG. 1A is a perspective view of an endoscopic forceps having an endeffector assembly, which incorporates all or a portion of the componentsof an OCT system, attached to a distal end of the forceps according tosome embodiments of the present disclosure;

FIG. 1B is a perspective view of a battery-operated endoscopic forcepshaving an end effector assembly, which incorporates all or a portion ofthe components of an OCT system, attached to a distal end of the forcepsaccording to another embodiment of the present disclosure;

FIG. 2 is a schematic side, cross-sectional view of an end effectorassembly incorporating optical components of an OCT system according toembodiments of the present disclosure;

FIG. 3 is a schematic diagram of a surgical system incorporating an OCTsystem according to other embodiments of the present disclosure;

FIG. 4 is a schematic diagram of a surgical system incorporating afiber-optic OCT system according to yet other embodiments of the presentdisclosure;

FIG. 5 is a flow diagram of a method of determining properties of tissuein an energy-based medical device according to embodiments of thepresent disclosure.

FIG. 6 is a schematic diagram of a surgical system according toembodiments of the present disclosure;

FIG. 7 is a schematic diagram of a surgical system incorporating afiber-optic OCT system and a light energy delivery system according toembodiments of the present disclosure;

FIGS. 8A and 8B are schematic diagrams of surgical systems incorporatinga fiber-optic OCT system and a light energy delivery system according toother embodiments of the present disclosure;

FIG. 9 is a schematic diagram of a surgical system incorporating afiber-optic OCT system and a light energy delivery system according toyet other embodiments of the present disclosure;

FIG. 10 is a flow diagram of a method of sealing tissue with anenergy-based medical device according to embodiments of the presentdisclosure; and

FIG. 11 is a flow diagram of a method of sealing tissue with anenergy-based medical device according to other embodiments of thepresent disclosure.

DETAILED DESCRIPTION

Embodiments of the presently-disclosed surgical instrument are describedin detail with reference to the drawings wherein like reference numeralsidentify similar or identical elements.

FIG. 1A shows an endoscopic surgical forceps 10 that incorporates theOCT systems described below. In FIG. 1A, forceps 10 is coupled to anenergy source (e.g., a generator 40) for generating energy, such aselectrical energy, ultrasonic energy, or light energy configured to sealtissue. The energy source (e.g., generator 40) is configured to outputenergy having desired characteristics. Forceps 10 is coupled to thegenerator 40 via a cable 34 that is configured to transmit energy andcontrol signals between the forceps 10 and the generator 40. Variousembodiments of the forceps 10 using various types of energy aredescribed below.

Forceps 10 is configured to support an end effector assembly 100.Forceps 10 includes various conventional features (e.g., a housing 20, ahandle assembly 22, a trigger assembly 25, and a rotating assembly 28)that enable forceps 10 and end effector assembly 100 to mutuallycooperate to grasp, seal, divide, and/or sense tissue. Forceps 10generally includes a housing 20 and a handle assembly 22 that includes amoveable handle 24 and a handle 26 that is integral with housing 20. Thehandle 24 is moveable relative to the handle 26 to actuate end effectorassembly 100 via a drive assembly (not shown) to grasp tissue.

In some embodiments, trigger assembly 25 may be configured to actuate aknife blade (not shown) or another component to sever tissue after asuccessful seal. Forceps 10 also includes a shaft 12 having a distalportion 16 that mechanically engages end effector assembly 100 and aproximal portion 14 that mechanically engages housing 20 proximaterotating assembly 28 disposed on housing 20. Rotating assembly 28 ismechanically associated with shaft 12 such that rotational movement ofrotating assembly 28 imparts similar rotational movement to shaft 12that, in turn, rotates end effector assembly 100.

End effector assembly 100 includes two jaw members 110, 120 havingproximal ends and distal ends (see FIG. 1A). One or both jaw members110, 120 are pivotable about a pin 19 and one or both jaw members 110,120 are movable from a first position wherein jaw members 110, 120 arespaced relative to another, to a second position wherein jaw members110, 120 are closed and cooperate to grasp tissue between the jawmembers 110, 120.

Each jaw member 110, 120 includes a tissue contacting surface disposedon an inner-facing surface thereof (see FIG. 1A). Tissue-contactingsurfaces cooperate to grasp and seal tissue held between thetissue-contacting surfaces. Tissue-contacting surfaces are connected togenerator 40 that can transmit energy through the tissue held betweenthe tissue-contacting surfaces.

First and second switch assemblies 30 and 32 are configured toselectively provide energy to end effector assembly 100. Moreparticularly, the first switch assembly 30 may be configured to performa first type of surgical procedure (e.g., seal, cut, and/or sense) and asecond switch assembly 32 may be configured to perform a second type ofsurgical procedure (e.g., seal, cut, and/or sense). It should be notedthat the presently-disclosed embodiments may include any number ofsuitable switch assemblies and are not limited to only switch assemblies30 and 32. It should further be noted that the presently-disclosedembodiments may be configured to perform any suitable surgical procedureand are not limited to only sealing, cutting, and sensing.

The handle assembly 20 may further include one or more lighttransmissive elements, such as a cable or optical fibers 34 thatconnects the forceps 10 to the generator 40. The cable 34 may include aplurality of optical fibers to transmit light through various paths andultimately to the OCT system incorporated into the end effector assembly100, which is described in further detail below.

First and second switch assemblies 30 and 32 may also cooperate with acontroller 42, which may be implemented by a logic circuit, a computer,a processor, and/or a field programmable gate array. The controller 42may automatically trigger one of the switches to change between a firstmode (e.g., sealing mode) and a second mode (e.g., cutting mode) uponthe detection of one or more parameters or thresholds. In someembodiments, the controller 42 is also configured to receive varioussensor feedback and to control the generator 40 based on the sensorfeedback. The embodiments of the present disclosure allow the jawmembers 110, 120 to seal and/or cut tissue using any suitable form ofenergy.

In some embodiments, the controller 42 may include a feedback loop thatindicates when a tissue seal is complete based upon one or more of thefollowing parameters: tissue temperature, optical sensing, change inimpedance of the tissue over time and/or changes in the optical orelectrical power or current applied to the tissue over time, rate ofchange of these properties and combinations thereof. An audible orvisual feedback monitor may be employed to convey information to thesurgeon regarding the overall seal quality or the completion of aneffective tissue seal.

Referring now to FIG. 1B, forceps 11 is shown having a portableconfiguration and includes an internal generator 50 for generatingenergy that is operably coupled to a battery compartment 52 via one ormore wires 50 a. In some embodiments, one or more battery operated laserdiodes or fiber lasers may also be used to provide a portable lightenergy source. The internal generator 50 may be configured to provideenergy to the end effector assembly 100. The battery compartment 52 maybe configured to receive one or more batteries 54 for providing suitableenergy to internal generator 50. In embodiments, the controller 42 mayalso be disposed within the forceps 11 (e.g., the housing 20).

Battery compartment 52 may be defined within any suitable portion ofhousing 20 of forceps 11, such as the fixed handle 26, as shown in FIG.1B. Suitable batteries may include, but are not limited to anickel-cadmium, lithium-ion, rechargeable, or any other suitable type.The location of internal generator 50 provides an operator increasedmaneuverability and convenience when performing a surgical treatmentwith forceps 11.

FIG. 2 illustrates an end effector assembly 100 according to someembodiments of the present disclosure, which is configured for use witheither surgical instrument 10 or surgical instrument 11 described aboveor any other suitable surgical instruments. However, for purposes ofsimplicity and consistency, end effector assembly 100 is described belowwith reference to instrument 10.

The end effector assembly 100 includes a first jaw member 110 thatincorporates a free-space OCT system 200. The OCT system 200 includes alight source 202, a beamsplitter 204, a reference mirror 206, and alight detector 208. The light source 202 is electrically coupled to thegenerator 40 to receive power and/or command signals from the generator40. The light detector 208 is electrically coupled the generator 40 toprovide light detection signals to the generator 40 and to receive powerfrom the generator 40.

In operation, the light source 202 (e.g., a monochromatic light source)emits a source beam 212 toward the beamsplitter 204, which is positioneddiagonally with respect to the source beam 212. The beamsplitter 204splits the source beam 212 into two halves: a first beam 214 and asecond beam 216. The first beam 214 is transmitted through thebeamsplitter 204 and then is reflected back from the tissue 205 towardsthe beamsplitter 204. The second beam 216 is reflected off thebeamsplitter 204 and then is reflected back towards the beamsplitter 204by the reference mirror 206. The back-reflected first beam 214 and theback-reflected second beam 216 are recombined by the beamsplitter 204into a recombined beam 218 that is detected by the light detector 208.The light detector 208 then transmits an electrical signal representingthe detected recombined beam 218 to the generator 40, which detects aninterference pattern based on the electrical signal and displays animage of the tissue 205 based on the detected interference pattern.

FIG. 3 is a schematic diagram of a surgical system 300 incorporating anOCT system having an optical assembly 305 and an electrical assembly310. As shown, the surgical system 300 includes an end effector assembly301 that incorporates the optical assembly 305 and the electricalassembly 310. The configuration of the optical assembly 305 is similarto the configuration of the optics in FIG. 2, except that the referencemirror 206 is disposed on a movable element 302 that can move thereference mirror 206 along a horizontal axis 304 to perform scanning ofthe tissue.

FIG. 3 also illustrates the electrical assembly 310 of the OCT systemthat receives the interference signal generated by the light detector208. The electrical assembly 310 may be disposed in the generator ofFIG. 1. The electrical assembly 310 includes an amplifier 312, ademodulator 314, and an analog-to-digital converter (ADC) 316. Theamplifier 312 amplifies the light detector signals and the demodulator314 demodulates the amplified signals as the reference mirror 206 ismoved along a horizontal axis 304. The demodulator 314 provides scansignals to the ADC 316, which converts the scan signals into digitalscan data. The digital scan data are then provided to a computer system320 that generates an image that is displayed on the display of thecomputer system 320. In addition or in the alternative, the computersystem 320 may analyze the digital scan data to identify the tissue, todetermine the status of the tissue being sealed, or to determine thatquality of a tissue seal.

In some embodiments, the computer system 320 may be incorporated intothe forceps 11 of FIG. 1B. For example, the processor of the computersystem 320 may be incorporated into the internal generator 50 of theforceps 11 and a display of the computer system 320 may be disposed onthe housing 20 of the forceps 11.

FIG. 4 is a schematic diagram of a surgical system 400 incorporating afiber-optic OCT system. A first portion 445 a of the fiber-optic OCTsystem is incorporated into the jaw members 110, 120 of the end-effectorassembly 440. The first portion 445 a of the fiber-optic OCT systemincludes a sample arm 410, which is incorporated into the first jawmember 110, and a reference arm 420, which is incorporated into thesecond jaw member 120. Alternatively, the reference arm 420 may beincorporated into the generator 40 of FIG. 1A.

A second portion 445 b of the fiber-optic OCT system is disposed outsideof the end-effector assembly 440. In some embodiments, the secondportion 445 b of the fiber-optic OCT system is disposed in the generator40 of FIG. 1A. In other embodiments, the second portion 445 b of thefiber-optic OCT system is disposed in the internal generator 50 of FIG.1B.

As shown in FIG. 4, the second portion 445 b of the fiber-optic OCTsystem includes two light sources: an imaging light source 402 and avisible light source 404. The imaging light source 402 may be abroadband source (e.g., a broadband, near-infrared source) thatgenerates an imaging beam to image tissue. Examples of broadband sourcesinclude super-luminescent diodes, fiber amplifiers, and femto-secondpulse lasers that generate light having a wavelength that ranges between800 and 1550 nanometers. The visible light source 404 generates avisible aiming beam. The outputs of the imaging light source 402 and thevisible light source 404 are optically coupled to a 2×1 optical coupler406, which combines the imaging light beam with the visible light beamso that a user can see the imaging light beam.

The light output from the 2×1 optical-fiber coupler 406 is coupled intooptical fiber 401 of the fiber-optic interferometer. The light is splitinto two optical fibers—a reference arm optical fiber 403 and a samplearm optical fiber 405—using a 2×2 optical-fiber coupler 408. Thereference arm optical fiber 403 is optically coupled to reference armoptics 420. The reference arm optics 420 includes a lens 422, such as aconvex lens, and a reference mirror 424. The lens 422 forms a light beamfrom the light emitted from the reference arm optical fiber 403 anddirects it to the reference mirror 424. The light reflects off thereference mirror 424 and travels back towards the optical-fiber coupler408 through the lens 422 and the reference arm optical fiber 403.

A sample arm optical fiber 405 is coupled to the sample arm optics 410,which transmits light to the tissue 205. The light is reflected from thetissue 205 back into the sample arm optical fiber 405. The light isreflected from the tissue as a result of changes in the index ofrefraction within the structure of the tissue, e.g., betweenintercellular fluid and collagen fibers. The light reflected back fromthe tissue 205 and the light reflected back from the reference mirror424 are recombined within the 2×2 fiber-optical coupler 408.

Because of the short coherence length of the broadband light source 402,the light reflected from the tissue and the light reflected from thereference mirror 424 will interfere constructively and destructivelyonly if the optical path lengths of the sample arm 410 and the referencearm 420 are matched. By changing the length of the reference arm, thetissue can be sampled at various depths.

The light recombined by the 2×2 fiber-optical coupler 408 is provided tothe optical detector 208, e.g., a photodiode via optical fiber 407. Theoptical detector 208 detects the interference between the lightreflected from the tissue and the light reflected from the referencemirror 424. During OCT imaging, the reference mirror 424 is scannedalong the longitudinal axis 425 A-A of the second jaw member 120 at aconstant velocity, thus allowing depth scans of the tissue (analogous toultrasound A-scans).

The sample arm optics 410 may be configured to perform lateral scansacross the tissue to construct two- and three-dimensional images. In theembodiment shown in FIG. 4, the sample arm mirror 414 may be rotatable415 about a transverse axis B-B of the first jaw member 110 to scan thetissue 205 along the longitudinal axis of the first jaw member 110. Thedetected interference signals from this scan are then used to constructa two-dimensional cross-sectional image of the tissue 205.

The optical detector 208 then transmits the detected interference signalto a processor 430, which forms an image of the tissue based on thedetected interference signal. The image is then displayed on a computerdisplay 320.

The surgical systems according to embodiments of the present disclosuremay generate images of a region of tissue so that a surgeon candetermine the status of the tissue after a sealing procedure. Forexample, the surgeon can use the generated images to verify whether ornot the tissue has been sealed or to determine whether or not the tissuehas been properly sealed.

FIG. 5 is a flow diagram of a method for determining properties oftissue in an energy-based medical device according to embodiments of thepresent disclosure. After starting in step 501, tissue is graspedbetween first and second jaw members of an energy-based medical devicein step 502. In step 504, a first light beam is directed to the tissuegrasped between the first and second jaw members and, in step 506, atleast a portion of the first light beam reflected from the tissue isreceived, e.g., by a light detector. In step 508, a second light beam isdirected to a reference mirror, and, in step 510, at least a portion ofthe second light beam reflected from the reference mirror is received,e.g., by the light detector.

In step 512, at least a portion of the first light beam reflected fromthe tissue and at least a portion of the second light beam reflectedfrom the reference mirror are combined to form an interference lightbeam. Finally, before ending in step 517, the interference light beam isdetected in step 514 and one or more tissue properties are determinedbased upon the detected interference light beam in step 516. The tissueproperties may include tissue type, cell type, disease state, or diseasepathology.

As described herein, the energy-based medical devices may have an OCTprobe embedded within the jaw members or the OCT probe may a retractableprobe that is deployed from the shaft of the medical device. In theseconfigurations, the OCT imaging may be performed prior to energydelivery when the jaw members clamp onto unsealed tissue, to determinethe structural density of the tissue. The structural density informationwould then be relayed to a controller to adjust the temperature and/orenergy to perform a tissue seal. The OCT imaging may also be performedafter performing a tissue sealing procedure so that the clinician candetermine the success and/or quality of the tissue seal. This type ofimaging/sealing medical device would be beneficial when sealing largevessels and thick tissue masses.

The OCT imaging may be used in combination with any type of energy-basedmedical device including medical devices that treat tissue using lightenergy, radio frequency energy, or ultrasound energy.

FIG. 6 is a schematic diagram of surgical system 600 that incorporatesan OCT probe. The surgical system 600 includes a controller 601, amemory 602, a display 603, an OCT system 610, and a generator or energysource 620. The controller 601 is electrically connected to the energysource 620 to control the energy output from the energy source 620. Theenergy source 620 may output light energy, electrical energy, orultrasonic energy. The controller 601 controls the amount of energyoutput from the energy source 620 to achieve a desired tissue effect.For example, in the case that the energy source 620 is a light energysource, the controller 601 controls the intensity and/or otherproperties of the light energy, e.g., polarization, to seal tissue thatis placed between the jaws of a surgical device.

According to the present disclosure, the controller 601 is electricallyconnected to the OCT system 610 to receive optical feedback information,which is used by the controller 601 to adjust the properties of theenergy output from the energy source 620. The optical feedbackinformation includes images that indicate the structural density and/orother properties of the tissue that is placed between the jaws of asurgical instrument. As described herein, all or a portion of thesurgical system 600 may be incorporated into a surgical instrument. Fora portable surgical instrument, all of the components of the surgicalsystem 600 may be incorporated into the surgical instrument.

The controller 601, which may be a processor, a digital signalprocessor, a central processing unit (CPU), or microprocessor, iscoupled to the memory 602, which may be a non-volatile memory such asROM or NVRAM. The controller 601 may retrieve instructions from thememory 602 and may execute the instructions to control the energy source620 based on feedback from the OCT system 610.

The OCT system 610 may be coupled to a display 603 that displays imagesof the tissue obtained by the OCT system 610. The display 603 may allowfor an operating mode in which a user may manually adjust the amount ofenergy output from the energy source 610 as the user views the display603.

According to the present disclosure, the OCT probe may be embedded in ajaw member of a tissue-sealing surgical device, e.g., an optical vesselsealer, which allows for imaging of tissue to be performed before andafter the tissue seal without device reconfiguration. The jaw member mayinclude a transparent window disposed at or near the tissue-contactingsurface of the jaw member to allow for imaging of tissue disposedbetween the jaw members of the tissue-sealing surgical device.

FIG. 7 is a schematic diagram of a surgical system incorporating afiber-optic OCT probe 710 and a light-energy delivery system 720. Thefiber-optic OCT probe 710 is incorporated into the first jaw member 110and the light-energy delivery system 820 is incorporated into the secondjaw member 120. The fiber-optic OCT probe 710 incorporates similarcomponents as the fiber-optic OCT system shown in FIG. 4. Thefiber-optic OCT probe 710 includes a sample arm 410 and a reference arm420 and an optical coupler 408. The OCT probe 710 may be opticallycoupled to the remaining components of an OCT system, which areillustrated above in FIG. 4.

The light-energy delivery system 720 includes a light source 721, anoptical fiber or other light waveguide 722, and a light distributionelement 723. The light source 721 generates light having an appropriateintensity and wavelength for sealing or otherwise treating tissuedisposed between the jaw members 110 and 120. The optical fiber 722carries the light generated by the light source 721 to the lightdistribution element 723, which forms and distributes a light beamperpendicular to or substantially perpendicular to the tissue-contactingsurface of the second jaw member 120.

A method of using the surgical system of FIG. 7 may include graspingtissue between the first and second jaw members 110 and 120, sensingoptical properties of the tissue using the OCT probe 710, and deliveringlight to tissue using the light-energy delivery system 720 based on thesensed optical properties of the tissue.

Vessels containing large and small amounts of collagen show differencesin structural density. Specifically, vessels with large collagen contenthave greater structural density than vessels with low collagen content.Thus, OCT may be used to detect the structural density of vessels, whichmay then be correlated to collagen content.

Preliminary testing has shown that vessels with a large amount ofcollagen content (e.g., the carotid artery) are more consistently sealedthan vessels with low collagen content (e.g., the femoral artery). Sincecollagen has a lower denaturation temperature than elastin, tissues withhigher collagen content may form seals at lower temperatures. Thus, OCTmay be used to determine the collagen or elastin content of tissue, andthe amount of energy delivered to the tissue may be controlled based onthe collagen or elastin contents of the tissue.

For example, OCT may be used to determine the amount of collagen and/orelastin in a vessel disposed between the jaw members 110 and 120. If theOCT probe 710 senses a large amount of collagen in the vessel, then thelight-energy delivery system 720 may deliver less energy to the vesselas compared to another vessel having a smaller amount of collagenbecause collagen has a lower denaturation temperature.

The tissue-contacting surface 220 of the first jaw member 110 may becoated with a reflective layer 715 adjacent the light output of thesample arm 410 of the fiber-optic OCT probe 710 so that the light beamfrom the light-energy delivery system 720 does not damage the componentsof the fiber-optic OCT probe 710.

In another mode of operation, the OCT probe 710 and the light-energydelivery system 720 may be operated simultaneously. In other words, theOCT probe 710 may sense optical properties of the tissue while thelight-energy delivery system 720 is delivering light to the tissue. Inthis mode of operation, a controller (not shown) coupled to thelight-energy delivery system 720 may control the intensity of the lightproduced by the light-energy delivery system 720.

FIGS. 8A and 8B are schematic diagrams of a surgical systemincorporating light-energy delivery systems 720 into both the first andsecond jaw members 110 and 120. Specifically, each of the first andsecond jaw members 110 and 120 includes a light source 721, an opticalfiber or waveguide 722, and a light distribution element 723. The OCTprobe 710 is movably coupled to the surgical device so that it can beinserted into and remove from between the first and second jaw members110 and 120.

In an example mode of operation, tissue is grasped between the first andsecond jaw members 110 and 120 of a surgical device. Next, the OCT probe710 is inserted 802 in between the first and second jaw members 110 and120 so that the distal end of the OCT probe 710 is disposed adjacent tothe tissue. Then, the OCT probe is operated to sense the properties ofthe tissue disposed between the first and second jaw members. Acontroller (not shown) coupled to the OCT probe 710 may determineparameters for light energy based upon the properties of the tissuesensed by the OCT probe 710.

Next, as illustrated in FIG. 8B, the OCT probe 710 is removed 804 fromin between the first and second jaw members 110 and 120. Then, thecontroller (not shown) may operate the light-energy delivery systems 720according to the determined parameters for the light energy. Thecontroller may operate the light-energy delivery systems 720 so thatthey simultaneously and/or alternatively deliver light to the tissue.

In other embodiments, the light energy delivery systems 723 may bereplaced by other energy delivery systems such as ultrasonic orelectrical energy delivery systems. These alternative energy deliverysystems may be operated in the same manner as described above withrespect to the light energy delivery systems 720.

FIG. 9 is a schematic diagram of a surgical system incorporating thelight energy delivery system 720 and a rotatable OCT probe 710. As shownin FIG. 9, the OCT probe 710 is rotatable 910 about the pin 901 from afirst position 902 to a second position 904. The first position 902 maybe a position at which the OCT probe 710 is not used and the secondposition 904 may be a position at which the OCT probe 710 is operated tosense properties of the tissue disposed between the jaw members 110 and120.

Thus, according to one method of operation, the first and second jawmembers 110 and 120 are operated to grasp tissue 205 and the OCT probe710 is rotated from the first position 902 to the second position 904.Then, the OCT probe 710 is operated to sense properties of the tissue205. After the OCT probe 710 senses the properties of the tissue 205,the OCT probe 710 may be rotated back to the first position 902 beforethe light-energy delivery system 720 delivers light to the tissue 205.Alternatively, the OCT probe 710 may remain in the second position 904while the light-energy delivery system 720 delivers light to the tissue205. Then, the light-energy delivery system 720 delivers light to thetissue 205.

FIG. 10 is a flow diagram of a method of sealing tissue using anenergy-based surgical device. After starting in step 1001, tissue isgrasped between the first and second jaw members of the surgical devicein step 1002. In step 1004, the properties of the tissue disposedbetween the first and second jaw members are sensed using an OCT probe.The sensed properties of the tissue may include the structural densityor structural profile of the tissue.

In step 1006, parameters of tissue-sealing energy are determined basedupon the properties of the tissue sensed by the OCT probe. Theseparameters may include power, voltage, and/or current in the case ofelectrosurgical and ultrasonic surgical devices. In the case oflight-based surgical devices, the parameters may include intensity,frequency, wavelength, and/or polarization. The parameters may alsoinclude temperature.

For example, if the OCT probe senses a high structural density ofvascular tissue disposed between the first and second jaw members, whichindicates a large concentration of collagen within the vascular tissue,the intensity and wavelength of a light beam generated by a light-basedsurgical instrument may be controlled so that a sufficient amount oflight energy is provided to the vascular tissue to denature the collagenwithin the vascular tissue.

Before the method ends in step 1009, tissue-sealing energy having thedetermined parameters is generated and applied to the tissue.

FIG. 11 is a flow diagram of another method of sealing tissue using anenergy-based surgical device. After starting, in step 1102, an OCT probeis inserted between first and second jaw members of a surgical devicenear tissue disposed between the first and second jaw members, in step1104. In step 1106, the structural density of the tissue disposedbetween the first and second jaw members are measured using the OCTprobe. In step 1108, parameters for tissue-sealing energy to be appliedto the tissue are determined based upon the structural density of thetissue measured in step 1106.

After determining the parameters for the tissue-sealing energy to beapplied to the tissue in step 1108, the OCT probe is removed frombetween the first and second jaw member in step 1110 so that the probeis not exposed the tissue-sealing energy. Then, before the method endsin step 1114, tissue-sealing energy having the determined parameters isgenerated and applied to the tissue.

The OCT systems described above may be modified to monitor differentproperties of tissue. For example, the sample arm optics 410 and thereference arm optics 420 of the OCT system could incorporatepolarization-altering optics (e.g., polarized lenses, plates, orwindows) to determine the tissue birefringence based upon the magnitudeof the back-reflected light.

The OCT systems may be configured to perform optical coherencemicroscopy for histology or tissue diagnostics. The OCT system mayincorporate optical elements to achieve resolutions comparable toconfocal microscopy but with increased depth of penetration. Forexample, the OCT system may incorporate optical elements having a highnumerical aperture (e.g., the lens 416 may have a high numericalaperture) to achieve high resolutions and a large penetration depth.

The surgical systems of the present disclosure (e.g., the surgicalsystem 400 of FIG. 4) may incorporate mechanisms for selectivelyapplying different optical elements to achieve different opticaleffects. In some embodiments, the surgical system 400 may include amechanism that switches between a standard optical element (e.g., thelens 416) and an optical element having a high numerical aperture. Inother embodiments, a polarization-altering optical element may beinserted in series with the standard optical element (e.g., the lens416).

In other embodiments, the OCT systems may be configured to perform colorDoppler optical coherence tomography (CDOCT) to measure tissueperfusion, i.e., the amount of blood that flows through tissue.

While several embodiments of the disclosure have been shown in thedrawings and/or discussed herein, it is not intended that the disclosurebe limited thereto, as it is intended that the disclosure be as broad inscope as the art will allow and that the specification be read likewise.Therefore, the above description should not be construed as limiting,but merely as exemplifications of particular embodiments. Those skilledin the art will envision other modifications within the scope and spiritof the claims appended hereto.

What is claimed is:
 1. A surgical system comprising: a housing; an endeffector assembly operably coupled to the housing, the end effectorassembly including: first and second jaw members each having a tissuecontacting surface, at least one of the first or second jaw membersmovable between a first, spaced-apart position and a second graspingposition; a sample arm optical assembly of an interferometer within thefirst jaw member, the sample arm optical assembly configured to transmita first light beam to tissue grasped between the first and second jawmembers and to receive at least a portion of the first light beamreflected from the tissue; a reference mirror of the interferometerwithin the first jaw member; a reference arm optical assembly of theinterferometer within the first jaw member, the reference arm opticalassembly configured to transmit a second light beam to the referencemirror and to receive at least a portion of the second light beamreflected from the reference mirror; and an optical coupler within thefirst jaw member and optically coupled to the sample arm opticalassembly and the reference arm optical assembly, the optical couplerconfigured to: provide the first light beam through a first output ofthe optical coupler to the sample arm optical assembly, provide thesecond light beam through a second output of the optical coupler to thereference arm optical assembly, and provide a third light beam through athird output of the optical coupler, the third light beam based on theportion of the first light beam reflected from the tissue and theportion of the second light beam reflected from the reference mirror;and a processor configured to process a signal based on the third lightbeam and obtain interference pattern data.
 2. The surgical systemaccording to claim 1, wherein the sample arm optical assembly includesmovable sample arm optics configured to scan the first light beam acrossthe tissue.
 3. The surgical system according to claim 1, wherein thesample arm optical assembly includes a light guide operable to translatealong and rotate with respect to a longitudinal axis of the first jawmember to scan the tissue.
 4. The surgical system according to claim 1,wherein the reference arm optical assembly is operable to translatealong a longitudinal axis of the first jaw member.
 5. The surgicalsystem according to claim 1, wherein the reference mirror is operable totranslate along a longitudinal axis of the first jaw member.
 6. Thesurgical system according to claim 1, wherein the first jaw member is atop jaw member and the second jaw member is a bottom jaw member.
 7. Thesurgical system according to claim 1, further comprising an imaginglight source that generates imaging light, the imaging light sourceoptically coupled to an input of the optical coupler.
 8. The surgicalsystem according to claim 7, further comprising: a visible light sourcethat generates visible light; and a second optical coupler comprising afirst input, a second input, and an output, the first input of thesecond optical coupler optically coupled to the imaging light source andthe second input of the second optical coupler optically coupled to thevisible light source, the second optical coupler configured to combinethe imaging light and the visible light and to transmit the combinedlight out of the output of the second optical coupler.
 9. The surgicalsystem according to claim 8, wherein a portion of the housing forms ahandle, and the imaging light source and the visible light source aredisposed within the handle.
 10. The surgical system according to claim1, wherein the sample arm optical assembly includes polarization opticsto allow for birefringence.
 11. The surgical system according to claim1, wherein the sample arm optical assembly and the reference arm opticalassembly are configured for optical coherence microscopy using a highnumerical aperture.
 12. A surgical system comprising: a first jaw memberand a second jaw member each having a tissue contacting surface, atleast one of the first or second jaw members movable between a firstspaced-apart position and a second grasping position, wherein the firstjaw member includes therein: a sample arm optical assembly configured toilluminate tissue grasped between the first and second jaw members witha first light beam, and receive from the tissue a portion of the firstlight beam reflected off the tissue, a reference arm optical assemblycomprising a reference mirror configured to reflect a portion of asecond light beam, and an optical coupler optically coupled to thesample arm optical assembly and the reference arm optical assembly,wherein the optical coupler is configured to: provide the first lightbeam from a first output of the optical coupler to the sample armoptical assembly, receive, at the first output, the reflected portion ofthe first light beam from the sample arm optical assembly, provide thesecond light beam from a second output of the optical coupler to thereference arm optical assembly, receive, at the second output, thereflected portion of the second light beam from the reference armoptical assembly, and provide a third light beam from a third output ofthe optical coupler, the third light beam based on the reflectedportions of the first and second light beams received at the first andsecond outputs respectively; and a processor configured to process alight detection signal and obtain interference pattern data therefrom,wherein the light detection signal is based on the third light beam. 13.The surgical system according to claim 12, wherein the processor isfurther configured to generate an image signal based on the interferencepattern data and transmit the image signal to a display device.
 14. Thesurgical system according to claim 12, further comprising a lightdetector configured to detect the third light beam and generate thelight detection signal therefrom.
 15. The surgical system according toclaim 14, further comprising: an energy source coupled to at least oneof the first and second jaw members, the energy source configured todeliver energy to at least one of the first jaw member or the second jawmember to seal the tissue grasped between the first and second jawmembers; and a controller coupled to the light detector and the energysource, the controller configured to control the energy source based onat least one measured property of the detected third light beam.
 16. Thesurgical system according to claim 15, further comprising a housingcoupled to the first and second jaw members, wherein at least one of theenergy source and the controller are disposed within the housing.